Block #334,250

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/29/2013, 9:11:26 AM · Difficulty 10.1574 · 6,473,706 confirmations

2CC
Cunningham Chain of the Second Kind

A sequence where each prime is double the previous prime minus one.

Block Header
Block Hash
548360012857d3aed035797ef5058e4a71ed1b52e56a3d051da282b9628d77de

Height

#334,250

Difficulty

10.157360

Transactions

8

Size

3.40 KB

Version

2

Bits

0a2848b7

Nonce

3,813

Timestamp

12/29/2013, 9:11:26 AM

Confirmations

6,473,706

Merkle Root

d2e39053cbbfa710957dd2b7664edf213694bd73e7088156c95eee33eb4c5e61
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

1.026 × 10⁹⁶(97-digit number)
10266923075904895736…35125791557390502401
Discovered Prime Numbers
p_k = 2^k × origin + 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin + 1
1.026 × 10⁹⁶(97-digit number)
10266923075904895736…35125791557390502401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.053 × 10⁹⁶(97-digit number)
20533846151809791473…70251583114781004801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.106 × 10⁹⁶(97-digit number)
41067692303619582947…40503166229562009601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.213 × 10⁹⁶(97-digit number)
82135384607239165894…81006332459124019201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.642 × 10⁹⁷(98-digit number)
16427076921447833178…62012664918248038401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.285 × 10⁹⁷(98-digit number)
32854153842895666357…24025329836496076801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.570 × 10⁹⁷(98-digit number)
65708307685791332715…48050659672992153601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.314 × 10⁹⁸(99-digit number)
13141661537158266543…96101319345984307201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.628 × 10⁹⁸(99-digit number)
26283323074316533086…92202638691968614401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.256 × 10⁹⁸(99-digit number)
52566646148633066172…84405277383937228801
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the Second Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,707,690 XPM·at block #6,807,955 · updates every 60s
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